Rotatable chain stopper

ABSTRACT

A rotatable chain stopper includes a base, an actuator operatively coupled to the base, and a pair of latches pivotably coupled to the base. The orientation of the base and position of the latches are responsive to extension of the actuator. The rotatable chain stopper may be used as a portion of chain jack assembly, such as on an offshore vessel. The rotatable chain stopper may used in a method of pulling-in, paying-out, and positioning of an anchor chain, such as for mooring an offshore vessel.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a Continuation of U.S. application Ser. No.15/603,293, filed on May 23, 2017 (allowed), which claims the benefit ofU.S. Provisional Patent Application No. 62/340,068, filed on May 23,2016 (now expired) and of U.S. Provisional Patent Application No.62/348,597, filed on Jun. 10, 2016 (now expired), of which theentireties of each are incorporated herein by reference.

FIELD

The present disclosure relates to chain stoppers for use with chainjacks or windlasses, both rotary and linear, and to methods of use ofthe same.

BACKGROUND

Chain jacks or windlasses are typically used to move heavy weight. Onetype of windlass, mooring windlasses, are used to pull-in or pay-outmooring lines to moor offshore vessels. Offshore mooring systems aretypically used to maintain offshore structures in position (i.e., onstation) within specified tolerances. Offshore structures, such asfloating production, drilling or construction platforms or spar buoys,generally are moored in a desired location through the use of mooringlines (e.g., chains or cables) secured between the offshore structureand anchors on the ocean floor. Mooring systems operate to providerestoring forces that act against environmental forces (e.g., wind,waves and currents) that move offshore structures out of position (i.e.,off station).

Enhanced control over the positioning of mooring lines maycorrespondingly enhance control over the positioning of associatedoffshore structures.

BRIEF SUMMARY

An embodiment of the present disclosure relates a rotatable chainstopper. The rotatable chain stopper includes a base, an actuator thatis operatively coupled to the base, and a pair of latches that arepivotably coupled to the base.

Another embodiment of the present disclosure relates to a chain jackassembly. The chain jack assembly includes a chain jack and a rotatablechain stopper. The rotatable chain stopper includes a base, an actuatoroperatively coupled to the base, and a pair of latches pivotably coupledto the base.

A further embodiment of the present disclosure relates to a method ofpositioning an anchor chain using a chain jack assembly that includes achain jack and a rotatable chain stopper. The rotatable chain stopperincludes a base, an actuator operatively coupled to the base, and a pairof latches pivotably coupled to the base. The method includespulling-in, paying-out, or combinations thereof the anchor chain usingthe chain jack. The method includes positioning the pair of latches togrip a link of the anchor chain. If the link is a vertical link, thepair of latches are positioned in a first position. If the link is aflat link, the pair of latches are positioned in a second position.Moving the pair of latches from the first position to the secondposition includes rotating the rotatable chain stopper by 90 degrees.The method includes gripping the link of the anchor chain with the pairof latches.

Some embodiments relate to a chain mooring windlass including a windlassframe, a chain wheel, a chain wheel axel extending through andoperatively coupled to the chain wheel and rotatably coupled to thewindlass frame, and drive assemblies operatively coupled to the chainwheel axel. The chain mooring windlass also includes a chain stopperconfigured to selectively rotate into: an open configuration allowingpassage of a chain through an opening formed by the chain stopper; and aclosed configuration with the chain stopper gripping a chain positionedwithin the opening formed by the chain stopper. The chain mooringwindlass with the chain stopper may be used in a method of pulling-in,paying-out, positioning, or combination thereof a mooring line.

The foregoing has outlined rather broadly the features and technicaladvantages of the present disclosure in order that the detaileddescription that follows may be better understood. Additional featuresand advantages will be described hereinafter, which form the subject ofthe claims. It should be appreciated by those skilled in the art thatthe conception and specific embodiment disclosed may be readily utilizedas a basis for modifying or designing other structures for carrying outthe same purposes of the present disclosure. It should also be realizedby those skilled in the art that such equivalent constructions do notdepart from the spirit and scope of the disclosure. The novel featureswhich are believed to be characteristic of the products, systems, andmethods, both as to its organization and method of operation, togetherwith further objects and advantages will be better understood from thefollowing description when considered in connection with theaccompanying figures. It is to be expressly understood, however, thateach of the figures is provided for the purpose of illustration anddescription only and is not intended as a definition of the limits ofthe present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the features and advantages of the system,products, and/or method so of the present disclosure may be understoodin more detail, a more particular description briefly summarized abovemay be had by reference to the embodiments thereof which are illustratedin the appended drawings that form a part of this specification. It isto be noted, however, that the drawings illustrate only variousexemplary embodiments and are therefore not to be considered limiting ofthe disclosed concepts as it may include other effective embodiments aswell.

FIG. 1 is a perspective view of a rotary chain jack or windlassincluding a chain stopper in accordance with certain embodiments of thepresent disclosure.

FIG. 2 is a perspective view of a linear chain jack including a chainstopper in accordance with certain embodiments of the presentdisclosure.

FIG. 3 is another perspective view of the rotary chain jack or windlassof FIG. 1.

FIG. 4 is another perspective view of the linear chain jack of FIG. 2.

FIG. 5 is a perspective view of the chain stopper of FIGS. 1 and 3 withthe latches in an open position.

FIG. 6 is another perspective view of the chain stopper of FIG. 5 withthe latches in a closed position.

FIG. 7 is a perspective view of the chain stopper of FIGS. 2 and 4,including latch adapters.

FIG. 8 is a perspective view of the chain stopper of FIGS. 2 and 4,without latch adapters.

FIG. 9 is another perspective view of the chain stopper of FIG. 8depicting a circular groove on a base of the chain stopper.

FIG. 10 is a perspective view of a dual chain mooring windlass inaccordance with certain embodiments of the present disclosure.

FIG. 11 is a side view of the dual chain mooring windlass of FIG. 10.

FIG. 12 is a cut-away, front view of a dual chain mooring windlassduring haul-in of a messenger chain in accordance with certainembodiments of the present disclosure.

FIG. 13 is a cut-away, side view of the dual chain mooring windlassduring haul-in of the messenger chain of FIG. 12.

FIG. 14 is a cut-away, front view of a dual chain mooring windlassduring transition from hauling in the messenger chain to hauling in amooring chain in accordance with certain embodiments of the presentdisclosure.

FIG. 15 is a cut-away, side view of the dual chain mooring windlassduring transition from hauling in the messenger chain to hauling in themooring chain of FIG. 14.

FIG. 16 is a cut-away, front view of a dual chain mooring windlassduring haul-in of the mooring chain in accordance with certainembodiments of the present disclosure.

FIG. 17 is a cut-away, side view of the dual chain mooring windlassduring haul-in of the mooring chain of FIG. 16.

FIG. 18 is a cut-away, front view of a dual chain mooring windlassduring positioning of the mooring chain in accordance with certainembodiments of the present disclosure.

FIG. 19 is a cut-away, side view of the dual chain mooring windlassduring positioning of the mooring chain of FIG. 18.

Products and methods according to present disclosure will now bedescribed more fully with reference to the accompanying drawings, whichillustrate various exemplary embodiments. Concepts according to thepresent disclosure may, however, be embodied in many different forms andshould not be construed as being limited by the illustrated embodimentsset forth herein. Rather, these embodiments are provided so that thisdisclosure will be thorough as well as complete and will fully conveythe scope of the various concepts to those skilled in the art and thebest and preferred modes of practice. For example, many of the exemplarydescriptions provided herein are concerned with chain jacks for mooringapplications. Aspects of the concepts described may, however, be equallyapplicable to chain jacks for non-mooring applications (e.g., movingheaving loads).

DETAILED DESCRIPTION

Certain embodiments of the present disclosure include a rotatable chainstopper for use in engaging a chain (e.g., an anchor chain) to, forexample, pull-in, pay-out, or position the chain, such as during mooringof an offshore vessel. The rotatable chain stopper may include twoopposing stopper latches, and may have an open “C” configuration or aclosed configuration. Other embodiments include a chain jack or windlassincluding the rotatable chain stopper, or to an offshore vesselincluding such a chain jack or windlass. Still, additional embodimentsinclude methods of use of the rotatable chain stopper, such as forpulling-in, paying-out, positioning, or combination thereof a mooringline. Embodiments of the rotatable chain stoppers disclosed herein maybe used with rotary chain jacks or windlasses, as shown in FIGS. 1 and3, or linear chain jacks, as shown in FIGS. 2 and 4. One skilled in theart would understand that the rotatable chain stoppers disclosed hereinare not limited to use with the particular chain jacks shown anddescribed herein.

As used herein, a “rotatable chain stopper” is a chain stopper in whichan orientation of the chain stopper can be changed relative to a definedaxis and/or a direction of extension of a chain (e.g., an anchor chain).For example, embodiments of the rotatable chain stopper disclosed hereinmay be reoriented “on the fly” such that latches of the rotatable chainstopper are capable of selectively gripping either vertical or flatlinks of a chain. As used herein, “flat links” and “vertical links”refer to adjacent links on a chain that are oriented 90 degrees orsubstantially 90 degrees from one another, as would be well understoodby one of ordinary skill in the art with reference to FIG. 1.

Rotary Chain Jack

With reference to FIGS. 1 and 3, an embodiment of a rotary chain jackincluding the rotatable chain stopper is depicted. Rotary chain jack 100includes dual chain wheel 5. Dual chain wheel 5 is configured to handleat least two different chain sizes. As shown in FIGS. 1 and 3, dualchain wheel 5 is operatively coupled with messenger chain 10 and anchorchain 15. Dual chain wheel 5 may be the same as or similar to the dualchain wheel disclosed in U.S. patent application Ser. No. 13/669,310,the entirety of which is incorporated herein by reference. While rotarychain jack 100 is shown as including dual chain wheel 5, the rotarychain jack disclosed herein is not limited to dual chain wheels. Forexample, other embodiments of the rotary chain jack may include a singlechain wheel.

Dual chain wheel 5 is rotatably coupled to frame 1 via axel 14. Frame 1is mechanically coupled to a portion of offshore vessel 200, such as thedeck. Frame 1 may be mechanically coupled to offshore vessel 200 viawelding and/or bolting, for example. Drive assemblies 32, such ashydraulic or electric motors, are operatively coupled to gear assembly6, and gear assembly 6 is operatively coupled to dual chain wheel 5. Insome embodiments, drive assemblies 32 include a motor, gearbox, andpinion. Drive assemblies 32 operate to drive gear assembly 6, gearassembly 6 operates to drive dual chain wheel 5, and dual chain wheel 5operates to pull-in or pay-out anchor chain 15 and/or messenger chain10, depending upon the direction of rotation of dual chain wheel 5. Whendual chain wheel 5 is not rotating, the position of anchor chain 15and/or messenger chain 10 may be maintained.

Rotary chain jack 100 includes rotatable chain stopper 20 a, which isdepicted in isolation from rotary chain jack 100 in FIGS. 5 and 6. Withreference to FIGS. 1, 3, 5 and 6, rotatable chain stopper 20 a includestwo latches 25 adapted to selectively engage with links of messengerchain 10 and anchor chain 15. Latches 25 are pivotably coupled to base30 a of rotatable chain stopper 20 a via latch pins 45. Latches 25 arepivotable about latch pins 45 to move between an open position, as shownin FIG. 5, and a closed position, as shown in FIG. 6. In the openposition, latches 25 are positioned to allow messenger chain 10 and/oranchor chain 15 to pass through rotatable chain stopper 20 a withoutlatches 25 engaging messenger chain 10 and/or anchor chain 15 (i.e.,latches 25 are clear of messenger chain 10 and/or anchor chain 15). Inthe closed position, gripping surfaces 26 of latches 25 engage withlinks of messenger chain 10 and/or anchor chain 15 operativelypositioned relative to rotatable chain stopper 20 a. Gripping surfaces26 may be concavities formed on the outer surface of latches 25 sized,shaped, and positioned to grip chains when latches are in the closedposition. Latches 25 are disposed in opposing positions on base 30 a,such that, when latches 25 are in the closed position, latches 25 gripmessenger chain 10 or anchor chain 15 from opposite sides thereof.

Latches 25 are adapted to coordinately move between the open and closedpositions. Latches 25 are responsive to latch actuator 35 and latchtiming link 40, such that when latch actuator 35 is extended, latches 25move into the open position, and when latch actuator 35 is retracted,latches 25 move into the closed position. Latch actuator 35 isoperatively coupled to the upper side of both latch pins 45 via actuatorconnection arms 50. Latch actuator 35 may be a linear actuator, such asa hydraulic or pneumatic cylinder. In other embodiments, latch actuator35 may be a rotary actuator. Actuator connection arms 50 extend abovelatch pins 45. Latch timing link 40 is operatively coupled to both latchpins 45 via timing levers 55. One of the timing levers 55 is generallyaligned with an actuator connection arms 50, and one of the timinglevers 55 is on the opposite side of latch pins 45.

Base 30 a is sized to support latches 25, and the loads supported bylatches 25. While base 30 a is shown as having a generally circularshape, the base is not limited to this particular configuration, and mayhave another shape.

When installed on rotary chain jack 100, as shown in FIGS. 1 and 3, base30 a and latches 25 are positioned with respect to dual chain wheel 5such that anchor chain 15 may be selectively secured by latches 25. Forexample, as shown, base 30 a is positioned with respect to dual chainwheel 5 such that anchor chain 15 hangs through the center of base 30 aand between latches 25 while the anchor chain 15 is engaged by chainwheel 5.

In the embodiment of rotatable chain stopper 20 a shown in FIGS. 1, 3, 5and 6, rotatable chain stopper 20 a has an open “C” configuration. Base30 a includes open side 31. Open side 31 of base 30 a is open withrespect to dual chain wheel 5 and provides clearance for messenger chain10. As described in more detail with respect to FIGS. 10-19, dual chainwheel 5 has an outer and inner ring of chain pockets, for operativeengagement with anchor chain 15 and messenger chain 10, respectively.The inner ring of chain pockets is positioned closer to the wheel hub ofdual chain wheel 5. The outer ring of chain pockets is sized tooperatively engage the links of anchor chain 15. The inner ring of chainpockets is sized to operatively engage the links of messenger chain 10.As the position of the inner and outer rings are different, the chainhangs closer to the hub of dual chain wheel 5 when the messenger chain10 is engaged with the chain wheel 5 than when anchor chain 15 isengaged with chain wheel 5, as explained in more detail below withreference to chain lines 38 a and 38 b. Open side 31 of base 30 a issized and positioned to accommodate the position of both messenger chain10 and anchor chain 15 as the chains hang from dual chain wheel 5. Openside 31 is positioned to face dual chain wheel 5 when in a firstposition, and is positioned at least 90 degrees from dual chain wheel 5(i.e., from first position) when in a second position.

Rotatable chain stopper 20 a and base 30 a are configured to rotateabout axis 133 (shown in FIG. 6). In a preferred embodiment, a chainhangs along axis 133. When a chain hangs along axis 133, rotatable chainstopper 20 a rotates about the chain. Rotatable chain stopper 20 arotates about axis 133 in response to actuator 56, such that actuator 56initiates rotation of rotatable chain stopper 20 a. Actuator 56 may be,for example and without limitation, a linear actuator, such as hydraulicor pneumatic cylinder. Actuator 56 is mechanically coupled to rotationarm 60 of base 30 a. Actuator 56 may be fixed with respect to dual chainwheel 5. In operation, when actuator 56 is extended, actuator 56 pushesagainst rotation arm 60 such that base 30 a rotates, thus rotatingrotatable chain stopper 20 a. In some embodiments, base 30 a, and thusrotatable chain stopper 20 a, is configured to be rotatable by at least90 degrees about axis 133 in response to actuator 56. In certainembodiments, base 30 a is configured to be rotatable by greater than 90degrees about axis 133 in response to actuator 56. Although a 90 degreerotation is preferred, it is understood that the amount of rotationdepends on the links of chain 15 and the need to align chain links withlatches 25.

While anchor chain 15 is suspended within rotatable chain stopper 20 a,ideally along axis 133, rotation of base 30 a allows latches 25 to beselectively positioned to support either vertical links 15 a or flatlinks 15 b of anchor chain 15, depending on which is most closelyaligned with latches 25. Thus, rotation of base 30 a allows latches 25to be selectively positioned to support anchor chain 15 irrespective ofthe orientation of the particular link adjacent latches 25. A chain jackin which latches are only capable of gripping vertical links or flatlinks is only capable of gripping every other link on the anchor chain.Thus, the ability of latches 25 to grip and support both vertical links15 a and flat links 15 b of anchor chain 15 halves the resolution atwhich the mooring tension may be set by rotary chain jack 100.

Base 30 a may be coupled to a portion of offshore vessel 200 (e.g., adeck thereof) in a manner that maintains a position of base 30 arelative to axis 133, while allowing a change in orientation of base 30a relative to axis 133 via rotation of base about axis 133. For example,base 30 a may be rotatably coupled to the deck of offshore vessel 200via a groove the same or similar to circular groove 3 of base 30 b oflinear chain jack 101, as shown in FIG. 9.

While rotatable chain stopper 20 a is shown in FIGS. 1, 3, 5 and 6 ashaving opening 31, in other embodiments the base of the rotatable chainstopper does not have such an opening. Whether or not base has anopening may depend upon any of various operational parameters including,but not limited to, the type of messenger chain of rotary chain jack100.

Linear Chain Jack

FIGS. 2 and 4 depict a linear chain jack with a rotatable chain stopperin accordance with certain embodiments of the present disclosure. Linearchain jack 101 includes linear actuators 103, upper chain stopper 120,and rotatable chain stopper 20 b. As described in more detail below, inoperation, upper chain stopper 120 operatively couples a chain passingthere-through while linear actuators 103 raise or lower the chain byraising or lowering upper chain stopper 120. Rotatable chain stopper 20b performs the same function as rotatable chain stopper 20 a describedabove, to selectively grip and support a vertical link 15 a or flat link15 b of anchor chain 15. Thus, in the embodiment shown in FIGS. 2 and 4,the linear actuators 103 and upper chain stopper 120 are configured topull-in and pay-out the anchor chain 15; whereas, in the embodimentshown in FIGS. 1 and 3, the dual chain wheel 5 is configured to pull-inand pay-out the anchor chain 15.

Linear actuators 103 may be hydraulic or pneumatic cylinders. Linearactuators 103 are operatively coupled to upper chain stopper 120, suchas via bolting, and may also be mechanically coupled to an offshorevessel. In operation, linear actuators 103 extend to raise upper chainstopper 120, and retract to lower upper chain stopper 120. When upperchain stopper 120 is gripping and supporting an anchor chain, raising orlowering upper chain stopper 120 correspondingly raises or lowers theanchor chain, thereby pulling-in or paying-out the anchor chain alongaxis 133, respectively. When upper chain stopper 120 is not gripping andsupporting an anchor chain, upper chain stopper 120 may be raised orlowered relative to the anchor chain. Upper chain stopper 120 includesopen side 131 on base 130. Open side 131 may be sized and positioned toaccommodate an anchor chain when linear chain jack 101 is being used topull-in or pay-out the anchor chain.

To lift an anchor chain, linear chain jack 101 may be positioned in theretracted position, as shown in FIGS. 2 and 4, latches 125 may grip andsupport the anchor chain, and latches 25 may be in the open positionsuch that latches 25 are not gripping or supporting anchor chain 15.Linear actuators 103 may then be extended until linear chain jack 101 isin the extended (lifted) position (not shown). Once linear chain jack101 is in the extended position, latches 25 may move into the closedposition such that latches 25 grip and support anchor chain 15. Oncelatches 25 are in the closed position, gripping and supporting anchorchain 15, latches 125 may be released from anchor chain 15 such thatlatches 125 are not gripping or supporting anchor chain 15. Latches 25may then maintain a position of anchor chain 15. Linear actuators 103may then be retracted to move linear chain jack 101 into the retractedposition. The operation of linear actuators 103 and upper chain stopper120 may be repeated as many times as desired to pay-out or pull-inanchor chain 15.

Latches 125 of upper chain stopper 120 may operate in substantially thesame manner as described with respect to latches 25. For example,latches 125 are rotatably coupled to base 130 via latch pins 145, suchthat latches 125 are rotatable about latch pins 145 to move between anopen position (not shown) and a closed position, as shown in FIGS. 2 and4. Latches 125 are responsive to latch actuator 135 and latch timinglink 140, such that when latch actuator 135 is extended, latches 125move into the open position, and when latch actuator 135 is retracted,latches 125 move into the closed position. Latch actuator 135 isoperatively coupled to the upper side of both latch pins 145 viaactuator connection arms 150. Latch actuator 135 may be a linearactuator, such as a hydraulic or pneumatic cylinder. Actuator connectionarms 150 extend above latch pins 145. Latch timing link 140 isoperatively coupled to both latch pins 145 via timing levers 155. Timinglevers 155 extend to opposite sides of latch pins 145.

FIGS. 7-9 depict rotatable chain stopper 20 b of FIGS. 2 and 4, but inisolation from linear chain jack 101. Rotatable chain stopper 20 bincludes all components of rotatable chain stopper 20 a as describedwith respect to FIGS. 1 and 3, with the exception that base 30 b doesnot have opening 31, as does base 30 a. Base 30 b includes opening 41through which an anchor chain may pass to be positioned in operativerelation to latches 25 on base 30 b.

The embodiment of rotatable chain stopper 20 b shown in FIG. 7 includeslatch adapters 65 coupled with latches 25. Latch adapters 65 may beattached to latches 25 to accommodate a smaller chain size, such as amessenger chain. As such, latch adapters 65 allow rotatable chainstopper 20 b to grip chains having smaller dimensions than chains thatcan be griped with latches 25 without latch adapters 65. In someembodiments, latch adapters 65 may be manually installed onto latches25. Latch adapters 65 are also shown in FIG. 2 on both latches 125 andlatches 25.

Each latch 25 of rotatable chain stopper 20 b includes bumper stopassembly, including bumper 51 on latch 25 and stop 53 on base 30 b. Inoperation, when latch 25 moves into the open position, bumper 51 engagesstop 53 to slow and/or stop further opening of latch 25. As such, thebumper stop assembly functions as a stop and/or damper for latch 25.While the bumper stop assembly is described with respect to rotatablechain stopper 20 b, one skilled in the art would understand that thebumper stop assembly may be included in other embodiments of therotatable chain stopper (e.g., rotatable chain stopper 20 a).

Base 30 b includes a top surface and a bottom surface opposite the topsurface. In the embodiment shown in FIG. 9, base 30 b includes circulargroove 3 on the bottom surface thereof. Circular groove 3 is configuredto mate with a cooperating shape attached to or part of offshore vessel200, such as a circular ridge. In operation, circular groove 3 ensuresthat base 30 b rotates about a fixed axis (e.g., axis 133). Whilecircular groove 3 is shown on rotatable chain stopper 20 b, but not onrotatable chain stopper 20 a, it would be understood by one skilled inthe art that a similar groove may also be on base 30 a to ensure thatbase 30 a rotates about a fixed axis (e.g., axis 133).

While linear chain jack 101 in FIGS. 2 and 4 is not shown coupled withan offshore vessel, it would be understood by one skilled in the artthat linear chain jack 101 could be coupled to an offshore vessel, suchas the one shown in FIGS. 1 and 3. Furthermore, linear actuators 103,with upper chain stopper 120, may be coupled with such an offshorevessel independently of rotatable chain stopper 20 b. In someembodiments, rotatable chain stopper 20 b is not mechanically coupled tolinear actuators 103 or upper chain stopper 120.

In certain embodiments, linear actuators 103, with upper chain stopper120, may be selectively coupled to an offshore vessel at differentlocations in relation to multiple, different rotatable chain stoppers 20b. As such, linear actuators 103, with upper chain stopper 120, may beselectively used with different rotatable chain stoppers 20 b to raiseand/or lower different anchor chains of the offshore vessel. Base 130 ofupper chain stopper 120 may have opening 131, allowing for rotatablechain stopper 20 b to be selectively positioned in operative relation toan anchor chain.

Operation of Rotary Chain Jack with Rotatable Chain Stopper

FIGS. 10-19 depict a chain mooring windlass including a rotatable chainstopper and the operation thereof in accordance with certain embodimentsof the present disclosure. While operation of a rotary chain jack (chainmooring windlass) is discussed with respect to FIGS. 10-19, one skilledin the art would understand that the discussion is substantiallyapplicable to the operation of a linear chain jack as well, with theexception that the rotational movement of the chain wheel is replacedwith a linear, reciprocating motion of the linear actuators with theupper chain stopper.

With reference to FIGS. 10-19, chain mooring windlass 100 b is shown,which is a rotary chain jack. Chain mooring windlass 100 b includes dualchain wheel 5 rotatably mounted onto frame 1 via axel 14. Axel 14extends through dual chain wheel 5. Frame 1 is mounted to a portion ofoffshore vessel 200.

Chain mooring windlass 100 b includes drive assembly 32. Drive assembly32 is operatively coupled dual chain wheel 5, which hauls anchor chain15 into or towards inboard hawse pipe 135 or deploys anchor chain 15outboard through outboard hawse pipe 136, depending upon the directionof rotation of dual chain wheel 5.

Chain mooring windlass 100 b includes chain wheel latch cylinder 39configured to ratchetedly engage with dual chain wheel 5. In theembodiment shown in FIGS. 10-19, chain wheel latch cylinder 39ratchetedly engages dual chain wheel 5 with chain wheel latch 39 a.

In some embodiments, anchor chain 15 may be mechanically coupled with ananchor (not shown). Anchor chain 15 is coupled with shackle 33. Inoperation, shackle 33 is configured to engage with teeth of dual chainwheel 5. Shackle 33 may be a back-to-back shackle connector. Shackle 33is coupled with messenger chain 10. In this manner, a continuous chainof two different chain sizes is formed.

In the embodiment show in FIGS. 10-19, the small wildcat profiles ofdual chain wheel 5 are sized and configured to couple with messengerchain 10. The large wildcat profiles of dual chain wheel 5 are sized andconfigured to couple with anchor chain 15, as discussed in U.S.application Ser. No. 13/669,310. In operation, while messenger chain 10is hauled in, anchor chain 15 may extend along chain line 38 a, andwhile anchor chain 15 is hauled in, anchor chain 15 may extend alongchain line 38 b.

The chain mooring windlass 100 b shown in FIGS. 10-19 includes rotatablechain stopper 20 a. Rotatable chain stopper 20 a includes actuator 56configured to selectively rotate rotatable chain stopper 20 a, asdescribed above.

FIGS. 12-19 depict chain mooring windlass 100 b in operation, inaccordance with certain embodiments of the present disclosure. FIGS. 12and 13 depict chain mooring windlass 100 b during haul-in of messengerchain 10. During haul-in of messenger chain 10, latches 25 of rotatablechain stopper 20 a are in the open position. When in the open position,as shown in FIGS. 12 and 13, chain line 38 a passes inboard of stopperlatches 25, by way of the open side of the “C” shaped rotatable chainstopper 20 a. When chain line 38 a is clear of rotatable chain stopper20 a, messenger chain 10 and shackle 33 do not engage latches 25 or thebody of rotatable chain stopper 20 a. In some embodiments, when chainline 38 a is clear of rotatable chain stopper 20 a, messenger chain 10and shackle 33 do not engage or touch latches 25 or the body ofrotatable chain stopper 20 a as they are hauled-in or payed-out.

While the messenger chain 10 is being hauled in, chain wheel latch 39 a,movable via chain wheel latch cylinder 39, is positioned to engage dualchain wheel 5. In some embodiments, chain wheel latch 39 a ratchetedlyengages dual chain wheel 5 as dual chain wheel 5 rotates. In theembodiment of FIG. 13, dual chain wheel 5 is rotated clockwise tohaul-in messenger chain 10, shackle 33, and anchor chain 15.

FIGS. 14 and 15 depict chain mooring windlass 100 b during transitionfrom hauling in messenger chain 10, as shown in FIGS. 12 and 13, tohauling in anchor chain 15, as shown in FIGS. 16-19. During transition,shackle 33 engages tooth 5 a of dual chain wheel 5. Tooth 5 a is shapedto receive shackle 33. In some embodiments, chain wheel latch 39 aratchetedly engages dual chain wheel 5 during the transition.

During the transition, latches 25 of rotatable chain stopper 20 a are inthe open position to allow anchor chain 15 to pass freely as anchorchain 15 transitions from chain line 38 a to chain line 38 b.

FIGS. 16-19 depict top chain haul-in. During top chain haul-in, anchorchain 15 is engaged with dual chain wheel 5, and anchor chain 15 extendsalong chain line 38 b. The center of rotation of rotatable chain stopper20 a may be a point located centrally between the two stopper latches25. In embodiments described above, the center of rotation was shown asaxis 133. In this manner, as rotatable chain stopper 20 a rotates,latches 25 rotate about the center of rotation. In some embodiments,chain line 38 b runs through the center of rotation.

During top chain haul-in, stopper latches 25 may be set to ratchetedlyengage with links of anchor chain 15. In this manner, stopper latches 25ratchet on the top part of alternating chain links. In some embodiments,stopper latches 25 rotate on the fly during top chain haul-in such thatstopper latches 25 engage each sequential chain link passing throughrotating chain stopper 20 a. FIGS. 16 and 17 on the one hand, and FIGS.18 and 19 on the other, show two positions in which stopper latches 25can engage anchor chain 15. To precisely position anchor chain 15,anchor chain 15 may be hauled in via rotating dual chain wheel 5. Oncein position, rotatable chain stopper 20 a is positioned such thatlatches 25 may engage with a link of anchor chain 15 that minimizes themovement of anchor chain 15 when anchor chain 15 is set down upon, andin engagement with latches 25. In operation, rotatable chain stopper 20a is rotated, such as by 90°, so that latches 25 may engage any link(vertical or flat) of anchor chain 15. As such, anchor chain 15 can bemore precisely positioned in that every link of anchor chain 15 can beengaged instead of every other link. Latches 25 secure and maintainposition of anchor chain 15. During top chain haul-in and precisepositioning of anchor chain 15, chain wheel latch 39 a may be disengagedfrom dual chain wheel 5.

Chain Stopping Method

Other embodiments of the present disclosure include use of a chainstopper assembly in accordance with any of FIGS. 1-19 during pulling-in,paying-out, and/or positioning mooring lines to moor offshore vessels.Certain embodiments of such a method may be performed using chainstopper assembly 20 a or 20 b, as described with reference to FIGS.1-19. Certain embodiments of such a method may be performed using achain jack assembly (e.g., rotary chain jack 100 or linear chain jack101) as described with reference to FIGS. 1-4, and 10-19.

The method includes pulling-in, paying-out, or combinations thereof ananchor chain using the chain jack (e.g., rotary chain jack 100 or linearchain jack 101). For example, the anchor chain may be pulled-in orpayed-out via rotation of a chain wheel or reciprocating motion of alinear actuators with an upper chain stopper.

The method includes positioning latches to grip a link of the anchorchain. If the link to be gripped is a vertical link, the latches arepositioned in a first position. If the link to be gripped is a flatlink, the latches are positioned in a second position. Moving thelatches from the first position to the second position is accomplishedby rotating the rotatable chain stopper by, for example, 90 degrees.Rotating the rotatable chain stopper includes extending the actuator ofthe rotatable chain stopper.

The method includes gripping the link of the anchor chain with thelatches. Gripping the link maintains a position of the anchor chain,such that the anchor chain is not pulled-in or payed-out while beinggripped by the latches of the rotatable chain stopper.

In some embodiments, the method includes attaching latch adapters to thelatches, and gripping a messenger chain coupled to the anchor chain withthe latch adapters.

In embodiments of the method in which the chain jack is a rotary chainjack including a chain wheel, the step of pulling-in, paying-out, orcombinations thereof the anchor chain includes rotating the chain wheel.

In embodiments of the method in which the chain jack is a linear chainjack including linear actuators and an upper chain stopper, the step ofpulling-in, paying-out, or combinations thereof the anchor chainincludes gripping the anchor chain with latches of the upper chainstopper, and raising, lowering, or combinations thereof the linearactuators. Raising or lowering the linear actuators results in acorresponding raising or lowering of the upper chain stopper, which,in-turn, results in a pulling-in or paying-out of the anchor chain.After gripping the link of the anchor chain with the latches of therotatable chain stopper, the latches of the upper chain stopper arereleased from anchor chain.

Although the present embodiments and advantages have been described indetail, it should be understood that various changes, substitutions andalterations can be made herein without departing from the spirit andscope of the disclosure. Moreover, the scope of the present applicationis not intended to be limited to the particular embodiments of theprocess, machine, manufacture, composition of matter, means, methods andsteps described in the specification. As one of ordinary skill in theart will readily appreciate from the disclosure, processes, machines,manufacture, compositions of matter, means, methods, or steps, presentlyexisting or later to be developed that perform substantially the samefunction or achieve substantially the same result as the correspondingembodiments described herein may be utilized according to the presentdisclosure. Accordingly, the appended claims are intended to includewithin their scope such processes, machines, manufacture, compositionsof matter, means, methods, or steps.

1-45. (canceled)
 46. A rotatable chain stopper assembly comprising: a base; latches coupled to the base; and latch adapters coupled with the latches.
 47. The assembly of claim 46, wherein the latch adapters are sized to grip a smaller chain size than a chain size that the latches are sized to grip.
 48. The assembly of claim 47, wherein the latches are sized to grip an anchor chain, and wherein the latch adapters are sized to grip a messenger chain.
 49. The assembly of claim 46, further comprising an actuator coupled to the base, wherein orientation of the base about an axis is responsive to the actuator.
 50. The assembly of claim 46, wherein the latch adapters, coupled with the latches, are pivotable between an open position and a closed position.
 51. The assembly of claim 46, further comprising a chain jack.
 52. The assembly of claim 51, further comprising a chain coupled to the chain jack, and wherein the latch adapters are selectively rotatable to support either vertical links or flat links of the chain.
 53. The assembly of claim 51, further comprising a chain coupled to the chain jack, wherein the latch adapters are pivotable between an open position and a closed position, wherein in the closed position the latch adapters grip a link of the chain, and wherein in the open position the latch adapters are clear of the chain.
 54. The assembly of claim 51, wherein the chain jack is a rotary chain jack or a linear chain jack.
 55. A rotatable chain stopper assembly comprising: a base; latches coupled to the base; and latch adapters selectively attachable and detachable with the latches.
 56. The assembly of claim 55, further comprising an actuator coupled to the base, wherein orientation of the base about an axis is responsive to the actuator, such that the latches, detached from the latch adapters, are selectively rotatable to support either vertical links or flat links of a first chain size; and such that the latch adapters, attached with the latches, are selectively rotatable to support either vertical links or flat links of a second chain size, wherein the second chain size is smaller than the first chain size.
 57. The assembly of claim 55, further comprising a chain jack.
 58. The assembly of claim 57, further comprising a mooring line coupled to the chain jack, the mooring line including a first chain coupled with a second chain, wherein the second chain has a smaller chain size than the first chain; wherein the latches, detached from the latch adapters, are pivotable between an open position and a closed position, wherein in the closed position the latches grip a link of the first chain, and wherein in the open position the latches are clear of the first chain; and wherein the latch adapters, attached with the latches, are pivotable between an open position and a closed position, wherein in the closed position the latch adapters grip a link of the second chain, and wherein in the open position the latch adapters are clear of the second chain.
 59. The assembly of claim 58, wherein the first chain is an anchor chain and the second chain is a messenger chain.
 60. A method of positioning an anchor chain, the method comprising: providing a chain jack assembly comprising a chain jack and a rotatable chain stopper, the rotatable chain stopper comprising a base and latches coupled to the base; pulling-in, paying-out, or combinations thereof a mooring line using the chain jack, the mooring line comprising an anchor chain coupled with a messenger chain; attaching latch adapters to the latches; positioning the latch adapters to grip a link of the messenger chain; and gripping the link of the messenger chain with the latch adapters attached to the latches.
 61. The method of claim 60, further comprising: pulling-in, paying-out, or combinations thereof the mooring line using the chain jack; removing the latch adapters from the latches; positioning the latches to grip a link of the anchor chain; and gripping the link of the anchor chain with the latches.
 62. The method of claim 60, wherein, if the link is a vertical link, the latch adapters are positioned in a first position, and if the link is a flat link, the latch adapters are positioned in a second position, wherein moving the latch adapters from the first position to the second position includes rotating the rotatable chain stopper.
 63. The method of claim 60, wherein the chain jack is a rotary chain jack including a chain wheel, and wherein pulling-in, paying-out, or combinations thereof the anchor chain includes rotating the chain wheel.
 64. The method of claim 60, wherein the chain jack is a linear chain jack including linear actuators and an upper chain stopper, the upper chain stopper including a base, upper latches coupled to the base, and upper latch adapters coupled with the upper latches; and wherein pulling-in, paying-out, or combinations thereof the mooring line includes gripping the messenger chain with the upper latch adapters and raising, lowering, or combinations thereof the linear actuators.
 65. The method of claim 64, further comprising gripping a link of the messenger chain with the latch adapters of the rotatable chain stopper; and, after gripping the link of the messenger chain with the latch adapters of the rotatable chain stopper, releasing the upper latch adapters of the upper chain stopper from messenger chain. 